No - First, Tesla doesn't do battery technology all by themselves. Their current Model S (and presumably also the Model X) use Panasonic battery technology. That makes battery tech R&D time/cost mostly an issue for that supplier.
Secondly, Elon Musk doesn't do all this stuff by himself. He is very brilliant, but Tesla also employs scores of brilliant engineers. Like in many companies, engineers can rotate through different projects. There are also multiple engineering teams that are working on different projects at the same time. Autopilot engineers aren't going to be slowing down the engineers who are working on the more affordable Model E.